901 resultados para contour tracing
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Purpose: To describe a new computerized method for the analysis of lid contour based on the measurement of multiple radial midpupil lid distances. Design: Evaluation of diagnostic technology. Participants and Controls: Monocular palpebral fissure images of 35 patients with Graves' upper eyelid retraction and of 30 normal subjects. Methods: Custom software was used to measure the conventional midpupil upper lid distance (MPLD) and 12 oblique MPLDs on each 15 degrees across the temporal (105 degrees, 120 degrees, 135 degrees, 150 degrees, 165 degrees, and 180 degrees) and nasal (75 degrees, 60 degrees, 45 degrees, 30 degrees, 15 degrees, and 0 degrees) sectors of the lid fissure. Main Outcome Measures: Mean, standard deviation, 5th and 95th percentiles of the oblique MPLDs obtained for patients and controls. Temporal/nasal MPLD ratios of the same angles with respect to the midline. Results: The MPLDs increased from the vertical midline in both nasal and temporal sectors of the fissure. In the control group the differences between the mean central MPLD (90 degrees) and those up to 30 degrees in the nasal (75 degrees and 60 degrees) and temporal sectors (105 degrees and 120 degrees) were not significant. For greater eccentricities, all temporal and nasal mean MPLDs increased significantly. When the MPLDs of the same angles were compared between groups, the mean values of the Graves' patients differed from control at all angles (F = 4192; P<0.0001). The greatest temporal/nasal asymmetry occurred 60 degrees from the vertical midline. Conclusions: The measurement of radial MPLD is a simple and effective way to characterize lid contour abnormalities. In patients with Graves' upper eyelid retraction, the method demonstrated that the maximum amplitude of the lateral lid flare sign occurred at 60 degrees from the vertical midline. Financial Disclosure(s): The authors have no proprietary or commercial interest in any of the materials discussed in this article. Ophthalmology 2012; 119: 625-628 (C) 2012 by the American Academy of Ophthalmology.
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More than 30% of Buccella peruviana (D'Orbigny), Globocassidulina crassa porrecta (Earland & Heron-Allen), Cibicides mackannai (Galloway & Wissler) and C. refulgens (Montfort) indicate the presence of cold Sub Antarctic Shelf Water in winter, from 33.5 to 38.3º S, deeper than 100 m, in the southern part of the study area. In summer, the abundance of this association decreases to less than 15% around 37.5-38.9º S where two species (Globocassidulina subglobosa (Brady), Uvigerina peregrina (Cushman) take over. G. subglobosa, U. peregrina, and Hanzawaia boueana (D'Orbigny) are found at 27-33º S in both seasons in less than 55 m deep in the northern part, and are linked with warm Subtropical Shelf Water and Tropical Water. Freshwater influence was signalized by high silicate concentration and by the presence of Pseudononion atlanticum (Cushman), Bolivina striatula (Cushman), Buliminella elegantissima (D'Orbigny), Bulimina elongata (D'Orbigny), Elphidium excavatum (Terquem), E. poeyanum (D'Orbigny), Ammobaculites exiguus (Cushman & Brönnimann), Arenoparrella mexicana (Kornfeld), Gaudryina exillis (Cushman & Brönnimann), Textularia earlandi (Parker) and thecamoebians in four sectors of the shelf. The presence of Bulimina marginata (D'Orbigny) between 34.1-32.8º S in the winter and 34.2-32.7º S in the summer indicates that the influence of the Subtropical Shelf Front on the sediment does not change seasonally, otherwise, the presence of Angulogerina angulosa (Williamson) in the winter, only in Mar del Plata (38.9º S), show that Malvinas currents are not influencing the sediment in the summer.
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Máster Universitario en Sistemas Inteligentes y Aplicaciones Numéricas en Ingeniería (SIANI)
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Máster Universitario en Sistemas Inteligentes y Aplicaciones Numéricas en Ingeniería (SIANI)
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Ziel der Arbeit ist die Analyse von Prinzipien der Konturintegration im menschlichen visuellen System. Die perzeptuelle Verbindung benachbarter Teile in einer visuellen Szene zu einem Ganzen wird durch zwei gestalttheoretisch begründete Propositionen gekennzeichnet, die komplementäre lokale Mechanismen der Konturintegration beschreiben. Das erste Prinzip der Konturintegration fordert, dass lokale Ähnlichkeit von Elementen in einem anderen Merkmal als Orientierung nicht hinreicht für die Entdeckung von Konturen, sondern ein zusätzlicher statistischer Merkmalsunterschied von Konturelementen und Umgebung vorliegen muss, um Konturentdeckung zu ermöglichen. Das zweite Prinzip der Konturintegration behauptet, dass eine kollineare Ausrichtung von Konturelementen für Konturintegration hinreicht, und es bei deren Vorliegen zu robuster Konturintegrationsleistung kommt, auch wenn die lokalen merkmalstragenden Elemente in anderen Merkmalen in hohem Maße zufällig variieren und damit keine nachbarschaftliche Ähnlichkeitsbeziehung entlang der Kontur aufweisen. Als empirische Grundlage für die beiden vorgeschlagenen Prinzipien der Konturintegration werden drei Experimente berichtet, die zunächst die untergeordnete Rolle globaler Konturmerkmale wie Geschlossenheit bei der Konturentdeckung aufweisen und daraufhin die Bedeutung lokaler Mechanismen für die Konturintegration anhand der Merkmale Kollinearität, Ortsfrequenz sowie der spezifischen Art der Interaktion zwischen beiden Merkmalen beleuchten. Im ersten Experiment wird das globale Merkmal der Geschlossenheit untersucht und gezeigt, dass geschlossene Konturen nicht effektiver entdeckt werden als offene Konturen. Das zweite Experiment zeigt die Robustheit von über Kollinearität definierten Konturen über die zufällige Variation im Merkmal Ortsfrequenz entlang der Kontur und im Hintergrund, sowie die Unmöglichkeit der Konturintegration bei nachbarschaftlicher Ähnlichkeit der Konturelemente, wenn Ähnlichkeit statt über kollineare Orientierung über gleiche Ortsfrequenzen realisiert ist. Im dritten Experiment wird gezeigt, dass eine redundante Kombination von kollinearer Orientierung mit einem statistischen Unterschied im Merkmal Ortsfrequenz zu erheblichen Sichtbarkeitsgewinnen bei der Konturentdeckung führt. Aufgrund der Stärke der Summationswirkung wird vorgeschlagen, dass durch die Kombination mehrerer Hinweisreize neue kortikale Mechanismen angesprochen werden, die die Konturentdeckung unterstützen. Die Resultate der drei Experimente werden in den Kontext aktueller Forschung zur Objektwahrnehmung gestellt und ihre Bedeutung für die postulierten allgemeinen Prinzipien visueller Gruppierung in der Konturintegration diskutiert. Anhand phänomenologischer Beispiele mit anderen Merkmalen als Orientierung und Ortsfrequenz wird gezeigt, dass die gefundenen Prinzipien Generalisierbarkeit für die Verarbeitung von Konturen im visuellen System beanspruchen können.
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Il trattato sottolinea quanto sia indispensabile avere un confronto fra le simulazioni numeriche effettuate col metodo Ray Tracing e le campagne di misure sperimentali. Sebbene le simulazioni numeriche comportino un impiego di tempo e risorse oneroso, una volta impostate risultano molto versatili e rapide nell'apportare cambiamenti ai relativi settaggi e ambiente di propagazione.
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In this Thesis, we study the physical properties and the cosmic evolution of AGN and their host galaxies since z∼3. Our analysis exploits samples of star forming galaxies detected with Herschel at far-IR wavelengths (from 70 up to 500 micron) in different extragalactic surveys, such as COSMOS and the deep GOODS (South and North) fields. The broad-band ancillary data available in COSMOS and the GOODS fields, allows us to implement Herschel and Spitzer photometry with multi-wavelength ancillary data. We perform a multicomponent SED-fitting decomposition to decouple the emission due to star formation from that due to AGN accretion, and to estimate both host-galaxy parameters (such as stellar mass, M* and star formation rate, SFR), and nuclear intrinsic bolometric luminosities. We use the individual estimates of AGN bolometric luminosity obtained through SED-fitting decomposition to reconstruct the redshit evolution of the AGN bolometric luminosity function since z∼3. The resulting trends are used to estimate the overall AGN accretion rate density at different cosmic epochs and to trace the first ever estimate of the AGN accretion history from an IR survey. Later on, we focus our study on the connection between AGN accretion and integrated galaxy properties. We analyse the relationships of AGN accretion with galaxy properties in the SFR-M* plane and at different cosmic epochs. Finally, we infer what is the parameter that best correlates with AGN accretion, comparing our results with previous studies and discussing their physical implications in the context of current scenarios of AGN/galaxy evolution.
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A method for automatic scaling of oblique ionograms has been introduced. This method also provides a rejection procedure for ionograms that are considered to lack sufficient information, depicting a very good success rate. Observing the Kp index of each autoscaled ionogram, can be noticed that the behavior of the autoscaling program does not depend on geomagnetic conditions. The comparison between the values of the MUF provided by the presented software and those obtained by an experienced operator indicate that the procedure developed for detecting the nose of oblique ionogram traces is sufficiently efficient and becomes much more efficient as the quality of the ionograms improves. These results demonstrate the program allows the real-time evaluation of MUF values associated with a particular radio link through an oblique radio sounding. The automatic recognition of a part of the trace allows determine for certain frequencies, the time taken by the radio wave to travel the path between the transmitter and receiver. The reconstruction of the ionogram traces, suggests the possibility of estimating the electron density between the transmitter and the receiver, from an oblique ionogram. The showed results have been obtained with a ray-tracing procedure based on the integration of the eikonal equation and using an analytical ionospheric model with free parameters. This indicates the possibility of applying an adaptive model and a ray-tracing algorithm to estimate the electron density in the ionosphere between the transmitter and the receiver An additional study has been conducted on a high quality ionospheric soundings data set and another algorithm has been designed for the conversion of an oblique ionogram into a vertical one, using Martyn's theorem. This allows a further analysis of oblique soundings, throw the use of the INGV Autoscala program for the automatic scaling of vertical ionograms.
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Gegenstand dieser Arbeit ist die nummerische Berechnung von Schleifenintegralen welche in höheren Ordnungen der Störungstheorie auftreten.rnAnalog zur reellen Emission kann man auch in den virtuellen Beiträgen Subtraktionsterme einführen, welche die kollinearen und soften Divergenzen des Schleifenintegrals entfernen. Die Phasenraumintegration und die Schleifenintegration können dann in einer einzigen Monte Carlo Integration durchgeführt werden. In dieser Arbeit zeigen wir wie eine solche numerische Integration unter zu Hilfenahme einer Kontourdeformation durchgeführt werden kann. Ausserdem zeigen wir wie man die benötigeten Integranden mit Rekursionsformeln berechnen kann.
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Lo scopo di questo lavoro di tesi è indagare le capacità di ALMA di osservare il continuo e le righe molecolari di emissione di HCN, HCO+ e HNC, in galassie lensate ad alto z, nelle prime fasi della loro formazione. Per farlo vengono utilizzate osservazioni ALMA di righe di emissione molecolare, relative a dati pubblici di Ciclo 0. Queste osservazioni vengono utilizzate per simulare in modo realistico l’emissione da parte di galassie ad alto z e la risposta osservativa del telescopio, assumendo diverse possibili geometrie di lensing. Inoltre le recenti osservazioni ALMA sono state utilizzate per aggiornare le relazioni già esistenti tra la luminosità FIR e la luminosità delle righe molecolari. Queste recenti osservazioni con maggiore sensibilità e risoluzione angolare, sembrano essere in buon accordo con le precedenti osservazioni. Per realizzare questo progetto di tesi, sono stati scaricati dall’archivio ALMA i dati non calibrati relativi a due sorgenti ben studiate: NGC1614, rappresentativa delle galassie di tipo starburst ed IRAS 20551-4250, un AGN oscurato. Il processo di calibrazione è stato ripetuto per esaminare le proprietà dei cubi di dati utilizzando il pacchetto Common Astronomy Software Applications (CASA). Le righe spettrali osservate e l’emissione del continuo sono state successivamente estrapolate ad alto z riscalando adeguatamente le distanze, le dimensioni delle sorgenti e le frequenze di emissione. In seguito è stato applicato un modello di lensing gravitazionale basato su quello di Lapi et al. (2012). Sono state considerate diverse configurazioni tra lente e sorgente per ottenere diverse geometrie delle immagini e diversi fattori di amplificazione. Infine stato utilizzato il software CASA per simulare le osservazioni ALMA in modo da verificare le capacità osservative del telescopio al variare della geometria del sistema. Per ogni riga molecolare e per l’emissione del continuo sono state determinate la sensibilit e la risoluzione che possono essere raggiunte con le osservazioni ALMA e sono state analizzate alcune strategie osservative per effettuare survey di righe spettrali in oggetti lensati. Inoltre stata analizzata la possibilit di caratterizzare oggetti starburst ed AGN dai rapporti tra le righe di emissione delle molecole traccianti di alta densit. Le prestazioni di ALMA consentiranno di distinguere e stimare i contributi relativi di SB ed AGN in galassie lensate a z > 2.5, quindi vicine alla loro presunta epoca di formazione (Lapi et al. 2010), in meno di 5 minuti di osservazione per qualsiasi fattore di magnificazione. Nel presente lavoro sono state inoltre discusse alcune strategie osservative per condurre survey o followup per osservare le righe di HCN(4-3), HCO+(4-3) e HNC(4-3) in galassie lensate a redshift 2.5 < z < 3, dimostrando che sono possibili per campioni statisticamente significativi in tempi relativamente brevi.
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Il progetto di tesi riguarda principalmente la progettazione di moderni sistemi wireless, come 5G o WiGig, operanti a onde millimetriche, attraverso lo studio di una tecnica avanzata detta Beamforming, che, grazie all'utilizzo di antenne direttive e compatte, permette di superare limiti di link budget dovuti alle alte frequenze e introdurre inoltre diversità spaziale alla comunicazione. L'obiettivo principale del lavoro è stato quello di valutare, tramite simulazioni numeriche, le prestazioni di alcuni diversi schemi di Beamforming integrando come tool di supporto un programma di Ray Tracing capace di fornire le principali informazioni riguardo al canale radio. Con esso infatti è possibile sia effettuare un assessment generale del Beamforming stesso, ma anche formulare i presupposti per innovative soluzioni, chiamate RayTracing-assisted- Beamforming, decisamente promettenti per futuri sviluppi così come confermato dai risultati.